Today we see TV in terms of electronic boxes and a viewing screen. We see little of the inner workings and the details are a matter of advanced electronics and solid-state physics. The viewer is far more aware of the programme content than of the technical aspects.

The earliest forms of TV in 1925-26 were totally different and the workings were very obvious. Television in those days was an awkward marriage between Victorian mechanical technology and valve electronics. The sitter was subjected to intense glare and had to sit close to a large whirling disc – and to obey John Logie Baird’s shouted instructions "Open your mouth", "move your head to the left" etc. The sitter was uncomfortable and often frightened. Baird recalled in his memoirs that one elderly and distinguished sitter (probably Sir Oliver Lodge) got his beard caught in the rotating disc.

Life was also tough for the viewer who had to peer closely at the outer edge of another large whirling disc to see a backlit picture about 3 x 5 cm. In the Baird "Televisor" (1930) the disc was enclosed in a metal cabinet, which made it safer. However the picture was small and it was impossible for more than one person to view at a time.

In the later mechanical era (1930-35) the television camera consisted of a "flying spot" scanner with a rotating mirror drum rather than a disc. The mirrors reflected a thin scanning beam which rapidly traversed the artiste. The effect was disorientating but it was an improvement on the blinding floodlights of the early days. The artiste had to use strange blue and black makeup, without which his or her features (eyebrows, lips etc.) would not come through properly.

A vivid first hand description of studio conditions has been given by BBC producer Lance Sieveking in his novel “The Perfect Witch” (1935). That book has been out of print for many years and it is unobtainable even on Amazon; an extract is given here:

Fabian tiptoed into Number Two Television Studio [ Broadcasting House]. It was a very large, bare room, the walls of which were lined with a felt-like material, painted white, with here and there a patch of black. Most of the room was in inky darkness…

A yard or two away, her back against a board on which was a black and white design, stood Virginia. A blindingly brilliant horizontal fountain of jigging dots of light swept across her face and the upper part of her body, so that she seemed to float there, shivering and immaterial like a sort of spiritual manifestation. Her face and neck were made-up with deep, contrasting, curved strokes of blue and grey-white.

She was just finishing a monologue. Fabian listened to her voice enchanted, and almost without knowing what had happened, allowed himself to be guided by [the producer] into the projection room. Here through a long narrow piece of glass he was able to look down the long stream of light-beams that rushed continuously across Virginia's face, scanning and scanning it, and turning a little he was able to see in a small screen her tiny image reduced to the scale on which the public saw her, and all the effect of the queer make-up was gone, leaving, in black and white, the face he knew so well, smiling at him and saying the last words of the monologue. … In another moment it was over. She bowed into the hurrying storm of brilliant dots, stepped aside into the darkness.

Someone stepped into the light and made an announcement, there was a pause, and then the whole studio was lighted normally. Fabian wandered into the middle of the floor and stood facing the scanning apparatus, which was running idle, and for a moment the little jigging dots played across his eyes. "Fancy yourself a television star?" said the voice of [the producer].

In the early electronic television era (1936-39) the pictures were slightly larger, but still only a 9 to 12 inches diameter on a cathode ray tube which gave them a blue-white tinge. Prolonged watching of television often led to eyestrain or headaches, as I recall from my teenage years. Since then there has been a gradual improvement of the technology towards better definition and larger picture size, and of course colour. The awkward and heavy cathode ray tubes, once at the cutting edge of television technology, have been replaced by flat-screen digital displays. In the cathode ray tube era it was fashionable to despise mechanical moving parts, but today they still play a part in computers and in modern video equipment, although hidden from view.